In the field of artificial tooth replacements where one tooth or even several teeth have to be replaced, the corresponding dental prosthesis are usually fixed in a patient's mouth via a dental implant which is fixed (e.g. like a screw) in the bone of a patient's jaw. Whereas there is usually plenty of space for placing a dental implant between two neighboring teeth, for instance, the situation is more tricky for the corresponding dental prosthesis. In order to achieve a qualitatively and aesthetically good result, a dental prosthesis has to fit almost perfectly between neighboring teeth on one hand and the connection between the dental prosthesis and the implant has to be very firm on the other hand, which can be achieved if the connection has basically no play. Besides the final location of a dental prosthesis within an oral environment it is also beneficial to ensure that a dental prosthesis can actually be inserted in between two neighboring teeth and, at the same time, can be connected with the implant.
In order to achieve the above-mentioned tasks and requirements, a possible solution is to determine the position and the orientation of a dental implant with respect to neighbouring teeth and the gingiva between these neighbouring teeth with a certain precision. Typically, this determination has to be performed in a situation, where the implant is not directly visible (e.g. the implant is below the upper edge of the gingiva).
In the prior art, the position and orientation of a dental implant is determined by attaching a scan body to the implant, determining the position and orientation of the scan body (e.g. with an optical scanning method), and determining the position and orientation of the implant relative to the position and orientation of the scan body. In some cases, the scanning procedure is carried out with help of a model which represents the situation of a patient's mouth or in other cases, the procedure is carried out directly in a patient's mouth. In the state of the art, various types of scan bodies with different geometrical properties are used. Once the positions and orientations of a scan body are known, this information is used to obtain the orientation and position of said implant. Whereas dental implants and scan bodies can be produced with high precision, the above-mentioned scanning procedure can be less precise, particularly in situations where distinctive parts, such as corners or edges, of a scan body are only partly visible.